基于小波分析的弹性板损伤识别

Damage identification research of elastic plate by means of the wavelet analysis

以含有损伤的四边简支矩形板为研究对象,采用等效刚度代替板内损伤带的刚度,建立了含有多条损伤带的弹性板有限元模型.运用有限元法分析板的振动特性,由Lanczos法计算得到沿板边两个方向的转角模态.通过对板的转角模态进行db1连续小波变换,利用小波系数模极大值点判断板内损伤带的位置,给出了一种识别弹性板损伤的方法.通过对一含3条损伤带的四边简支矩形板进行损伤识别,验证了方法的有效性.

This research is focused on the four sides simply-supported damaged rectangular plate, using the equivalent stiffness in place of the damaged plate stiffness, and an elastic finite element plate model with several damage regions is established. Adopting the finite element method analysis the vibration characteristic of the plate,the angle displacement mode of the plate along its two directions is calculated by the Lanczos method. The angle displacement mode is analyzed as signal by dbl wavelet, the location of the declining stiffness is identified by the maximum of wavelet coefficients, introducing a method of locating the elastic damaged plate. Three damaged regions in rectangular simply supported plate are being recognized, indicating this method is effective and accurate.